Method of Performing Transfer Printing on Sheets of Paper

Abstract

There is provided a method of performing transfer printing on sheets of papers capable of stopping a film from running while the film is kept apart from a cylinder and patterns of the film are not transferred onto the sheets, and of joining the film to the cylinder with the film and the cylinder matched in speed and phase at the resumption of running. While the cylinder is rotated at a specific speed, the film is on a first travel path and stopped from running. Before the film is moved from the first travel path to a second travel path to be joined to the cylinder, four steps are performed so that the running speed of the film is matched to the rotation speed of the cylinder, and the phase of marks provided on the film at equal intervals is matched to the phase of a gripper of the cylinder.

1 . A method of performing transfer printing on a sheet of paper using a printing press including a film running mechanism having a first travel path and a second travel path, the first travel path being apart from a cylinder, the second travel path being proximate to the cylinder, a transfer film being capable of running both on the first and second travel paths, patterns of the film being transferred onto the sheet by pressing the film that is being running along the second travel path onto the sheet conveyed while being gripped with a gripping jaw of the cylinder, the method including: while rotating the cylinder at a specific speed, locating the film on the first travel path to stop the film from running, performing a series of steps to match a running speed of the film to the rotation speed of the cylinder and to match a phase of marks provided at equal intervals on the film to a phase of the gripping jaw of the cylinder, and then causing the film from the first travel path to the second travel path to be joined to the cylinder, the series of steps including:
 (a) choosing a particular mark out of the marks on the film while the film is held stopped from running on the first travel path;   (b) calculating a travel path length in the second travel path from a position of the particular mark to a contact starting point where the film meets the sheet of paper;   (c) calculating a time required for running the film just for the travel path length on the assumption that the film that is held stopped is run just for the travel path length along the first travel path under a predetermined acceleration condition for acceleration of the cylinder from its stopped state up to the specific speed and a condition for the specific speed after the acceleration; and   (d) causing the film to start running along the first travel path at a point in time where the gripping jaw locates at a position from which the gripping jaw is to reach the contact starting point after the time calculated in the step (c), to match the speed of the film to the specific speed of the cylinder within the time calculated in the step (c).   
   
   
       2 . The method according to  claim 1 , wherein
 given that the film that is held stopped is run under the predetermined acceleration condition of the step (c), a mark locating downstream of the aforesaid mark in a running direction may be chosen in the step (a), in a case where the travel path length is equal to or shorter than a travel distance to be reached when the predetermined acceleration is completed.